1. Field
Embodiments relate to 2-dimensional nanostructured tungsten carbide and a method for fabricating same. More particularly, embodiments relate to 2-dimensional nanostructured tungsten carbide of various shapes, particularly tungsten carbide of nanowall structure, obtained by control of the alignment of nanostructure during growth of tungsten carbide through control of the degree of supersaturation and a method for fabricating same.
2. Description of the Related Art
Nanostructured materials have attracted great interest in various nanotechnology applications due to their outstanding physical and chemical properties. Great efforts have been directed to the synthesis of specifically aligned nanostructured materials to exploit their properties varying with their geometrical alignment. Recently, vertically aligned 2-dimensional nanostructures, so-called nanowalls, of carbon, zinc oxide (ZnO) and cobalt oxide (Co3O4) have been reported. Further, it is known that NiO nanowalls are electrochemically superior to NiO nanoparticles.
Due to high aspect ratio, short diffusion length for mass and charge transport and high in-plane continuity on a substrate, nanowall structures are ideal for lithium batteries, energy storage media, field electron emitters, and so forth.
Tungsten carbide (WC) has been widely adopted in various fields due to high melting point, superior hardness, low friction coefficient, high oxidation resistance and superior electrical conductivity. Recently, it was reported that nanostructured tungsten carbide has platinum (Pt)-like catalytic properties in chemisorption of hydrogen and oxygen. Hence, it has a potentially of replacing the expensive platinum catalyst.
Currently, there are few researches on the synthesis of nanostructured tungsten. Synthesis of nanometer-sized WC needles on a tungsten tip by catalytic deposition (T. Arie, S. Akita and Y. J. Nakayama, J. Phys. D: Appl. Phys., 1998, 31, L49) was the first report and synthesis of WC nanotubes by thermal decomposition and synthesis of WC2 nanowires by thermal annealing of WCx films under nitrogen atmosphere were reported.
However, the nanostructured tungsten carbide materials fabricated by these methods have 1-dimensional structures. Vertically aligned 2-dimensional nanostructures of tungsten carbide, i.e. nanowall structures of tungsten carbide, have not been reported to date.